Set model.id if attributes contain a parsed version of idAttribute

src/base/model.js

@@ -113,16 +113,20 @@ ModelBase.prototype.initialize = function() {};
  *
  * This tells the model which attribute to expect as the unique identifier
  * for each database row (typically an auto-incrementing primary key named
- * `"id"`). Note that if you are using {@link Model#parse parse} and {@link
+ * `'id'`). Note that if you are using {@link Model#parse parse} and {@link
  * Model#format format} (to have your model's attributes in `camelCase`,
  * but your database's columns in `snake_case`, for example) this refers to
- * the name returned by parse (`myId`), not the database column (`my_id`).
+ * the name returned by parse (`myId`), not the actual database column
+ * (`my_id`).
  *
- * If the table you're working with does not have an Primary-Key in the form
- * of a single column - you'll have to override it with a getter that returns
- * null. (overriding with undefined does not cascade the default behavior of
- * the value `'id'`.
- * Such a getter in ES6 would look like `get idAttribute() { return null }`
+ * You can also get the parsed id attribute value by using the model's
+ * {@link Model#parsedIdAttribute parsedIdAttribute} method.
+ *
+ * If the table you're working with does not have a Primary-Key in the form
+ * of a single column you'll have to override it with a getter that returns
+ * `null`. Overriding with `undefined` does not cascade the default behavior of
+ * the value `'id'`. Such a getter in ES6 would look like
+ * `get idAttribute() { return null }`.
  */
 ModelBase.prototype.idAttribute = 'id';
 
@@ -157,6 +161,34 @@ ModelBase.prototype.get = function(attr) {
   return this.attributes[attr];
 };
 
+/**
+ * @method
+ * @description
+ *
+ * Returns the model's {@link Model#idAttribute idAttribute} after applying the
+ * model's {@link Model#parse parse} method to it. Doesn't mutate the original
+ * value of {@link Model#idAttribute idAttribute} in any way.
+ *
+ * @example
+ *
+ * var Customer = bookshelf.Model.extend({
+ *   idAttribute: 'id',
+ *   parse: function(attrs) {
+ *     return _.mapKeys(attrs, function(value, key) {
+ *       return 'parsed_' + key;
+ *     });
+ *   }
+ * });
+ *
+ * customer.parsedIdAttribute() // 'parsed_id'
+ *
+ * @returns {mixed} Whatever value the parse method returns.
+ */
+ModelBase.prototype.parsedIdAttribute = function() {
+  var parsedAttributes = this.parse({[this.idAttribute]: null})
+  return parsedAttributes && Object.keys(parsedAttributes)[0]
+}
+
 /**
  * @method
  * @description  Set a hash of attributes (one or many) on the model.
@@ -190,7 +222,10 @@ ModelBase.prototype.set = function(key, val, options) {
   const prev    = this._previousAttributes;
 
   // Check for changes of `id`.
-  if (this.idAttribute in attrs) this.id = attrs[this.idAttribute];
+  if (this.idAttribute in attrs)
+    this.id = attrs[this.idAttribute];
+  else if (this.parsedIdAttribute() in attrs)
+    this.id = attrs[this.parsedIdAttribute()];
 
   // For each `set` attribute, update or delete the current value.
   for (const attr in attrs) {

test/integration/model.js

@@ -127,7 +127,7 @@ module.exports = function(bookshelf) {
       });
     });
 
-    describe('id, idAttribute', function() {
+    describe('#id, #idAttribute', function() {
       it('should attach the id as a property on the model', function() {
         var test = new bookshelf.Model({id: 1});
         equal(test.id, 1);
@@ -141,6 +141,20 @@ module.exports = function(bookshelf) {
 
         equal(test.id, 2);
       });
+
+      it('#id should be set when model has custom parse method', function() {
+        var TestModel = bookshelf.Model.extend({
+          idAttribute: 'test_id',
+          parse: function(attrs) {
+            return _.mapKeys(attrs, function(val, key) {
+              return _.camelCase(key);
+            });
+          }
+        });
+        var test = new TestModel({test_id: 2}, {parse: true});
+
+        equal(test.id, 2);
+      });
     });
 
     describe('query', function() {